Hydraulic upright drill



Aug l, 1931. A. L. DE'LEEUW' 1,816,829 HYDRAULIC UPRIGHT DRILL.

I Filed Dec. 4, 1926 4 Sheets-Sheet -1 A. L.- DE LEEUW HYDRAULIC UPlIGHT DRILL Filed Dec.

.Aug. 4, 1931'.

4, 1923 4 Sheets-Shee 2 awuemto'c Aug. 4, 1931. k A. L. DE LEEUW 1,816,829

v HYDRAULIC UPRIGHT DRILL I Filed Dec. 4, 19 26 4 Sheets-Shee 3 awuemtoz I Gum/W21 Aug. 4,1931. A L. DE LEEUW HYDRAULIC UPRIGHT DRILL Filed Dec. 4, 1926 I 4 Sheets-Shae?- 4 Qvwwtoz MM 0%. 94 M @lflmew u Patented Aug. 4, 1931 ADOLPH L. DE LEEUW, OF PLAINFIELD, NEW JERSEY I-IYDRAULIC UIPRIGHT DRILL Application filed December 45 1926. Serial No. 152,681.

This invention concerns a machine tool and as specifically shown an upright drill although many of the objects and means disclosed herein are not limited to the specific ype of machine tool shown.

In metal working machines various means have been developed for rotating the spindie carryingthe Working tool and for moving the tool into engagement with the stock 10 tobe machined and for moving the tool through its Working stroke. Purely mechanical means for advancing the tool through its working stroke were subject. to certain defects which it was sought to over- 5 .come. For example a positive feed such as a wormand nut engaging therewith would -often result in broken parts .in the event that too much resistance was met with.

With the development of fluid pressure 20 means it was discovered that such means could be applied to machine tools for translating certain members in a very advantageous manner, thereby overcoming many of the objectionable features of a rigid, positive, pure- :5 ly'mechanical means for transmitting power to the element to be moved.

A piston actuated by a hydraulic fluid could be connected up to translate a movable working element to give it a smooth :0 steady travel and one which was as strong as desired but yet yielding tounusual resist-' ance or a positive stop.

One of the many defects in the mechanicaldrives was the presence of back lash or play 5 hetween the parts especially after the parts became worn. This was practically eliminated by the fluid pressure means and especially so by the use of differential pistons wherein a fluid acted continuously onthe 0 piston of smaller area tending to moveit in one direction, and thereby taking up the play or back lash. By intermittently andselective- 1y applying fluid to the opposite side of the piston it was caused to move against the op- 5 posing lesser pressure and to perform its machining operation. Both elastic fluids such as air and inelastic fluids such as oil have been used. Each of these have defects in certain cases. The 'oil may rove too rigid and positive while the air often proved too flexible resulting in uneven movement due to compression of the gas.

In the general utilization of fluid pressure in connection with a cylinder and piston for operating various devices such as the ma- 5; chine tool herein disclosed an objectionable feature also developed which was the loss of fluid through the piston rod packing. With the increasingly high pressures which are being used going up to 1,000 lbs. and even much higher, this defect has become more noticeable and is the source of much annoyance, loss of pressure and of fluid, and necessitating the expenditure of considerable time, labor and money. Even when low pressure is used the constant wear on packing soon results in leakage and requires freguent replacement or attention to the packmg.

One of the main objects of this invention 70 consists of'a novel arrangement whereby this leakage is practically eliminated or if any leakage takesplace the fluid passes directly into the system without any attention from the operator. This novel feature is arrived .75, at by providing two pistons of unequal area arranged at opposite ends of the piston rod 'each piston being arranged in its corresponding cylinder with an intervening wall throughwhich the rod passes. Reci roca-- tion is obtained by admitting an by raulic fluid to the-chambers on opposite sides of the wall whereby any leakage-from one cylinder necessarily passes into the other cylinder. The whole results in a very much sims! plified cylinder construction and one inexpensive to manufacture.

Another object of the present invention is to apply, in amachine tool such as the drill shown, acombination of two fluids, one elas- 1m tie and] the other inelastic for causing the translation of the working spindle. On the working strokethe piston means disclosed for applying the power is actuated by an hydraulic fluid, the. opposing fluid. which The present invention has an-advantagein that by the use of two fluids the pressures of the two fluids need not be the same and can be adapted to there uirements and to what. would be best under t e o erating conditions.

. .A further object and 'a vantage lies in the means relative to the working spindle. Heretofore'the cylinder and piston means have .9.

arrangement of the fluid pressure operating been principally connected directly to v the movable spindle. 'In an upright drill in which a rotatable spindle has a vertical translation the cylinder and piston were attached ,suspnded part ofthe drill and the weight of the hydraulic fluid-at times rest-ingon thepiston interfering with manual operation of in a Vertical manner directly to the upper "end-of the spindle, thereby placing a-large amount of weight and strain on asomewhat the spindle. Also with varying amounts of liquid resting on the piston at different spindle is made easier.

., The articular combination of manual r .pointsgi'n the stroke the force exerted was not Y always the same. With the present device the cylinder and pistonmeans are arranged hori-' zontally withsuitable connections therefrom many of the variations in force applied are eliminated and manual adjustment of the means or translatin the spindle with the fluid pressuremeans orms another object of this invention. Suchcombina'tions are broad- 1y old but heretofore various means such as by-pass valves have been found necessary for rendering the fluid pressure'entirel inoperative while manual movement was eing undergone as e. g. quickly bringing the tool 1 into engagement with the stock. lVith the fluid pressure means herein disclosed the fluid pressure acts constantly in one direction but isof such a flexible nature "as to 11-- able thus resultin as'a whole in a fluid preslow of-manual movement in to. y

A still further object of the invention lies in the application of a particular type-of opposition there- Slide'valve which gives a more accurate and reliable controlof the fluid. The means for operating the control valve have been simplified and made more dependsure operated mac ine tool which is more flexoperation. Other objects and'advantages willbe in ible yet, accurate, strong. and reliable inJ-its Figure 1 1s anelevational view of the up-' per portion'of a vertical drill showing the fluid pressure operating means, connected thereto. Fig. 2 is also-an elevational view of the same drill looking from the front. Fig.

3 is a plan view thereof.--- Fig. 4 is a diagrammatic view showing the fluid pressure means .and Fig. '5 is a view similar to Fig. 1 but showing a difierent type of fluid pressure cylinder for operatingthe drill. The main features of the machine shown comprise a headof a vertical drill having mounted therein the s indle 11 designed to receive a verticalmotion from the fluid pressure means 12. and also from the hand wheel 13 both geared to the horizontally arranged shaft 14. The lower end of the spindle 15 is designed to accommodate a tool such as the drill 2- and receives a rotary motion from the gearingshown in dotted lines in. Fig. 1. Such gearing comprises a spur-gear 16 fixed on the shaft 17 for drivingthrough the gear 18 the gear 19v splined on the spindle portion for vertlcally moving the spindle. Thus i 15'. The means for giving the spindle a ro of driving means desired could be used in place thereof.

Referring more particularly to the fluid pressure means for translating the spindle in a vertical direction, such means comprises a cylinder 20 arranged in tandem with. the cylinder'21' with the pistons arranged. in the respective cylinders and connected together by the piston rod 22 passing through the common wall or cylinder head 23 to be later described in more detail. Connected to the larger piston isthe rack 24 engaging with the rack gear 25 mounted on and rigid with the shaft 14.

The shaft 14 has also mounted thereon at one end thereof the large wheel 13 for manual rotation of the shaft whereby the drill spindle may receive its vertical movement either or by the fluid pressure means shown has theadvantage of relieving the spindle of the weight of the pistons and the fluid in contact therewith. The, weight of thefluid in the construction shown has no tical manner over the spindle with the pistons directly-attached to the spindle. It may be seen that in the latter case the weight of fluid on the pistons would vary for different points in the stroke and the force required to overcome such weight through the wheel 13,

forexample, might at certain points of the stroke be considerable.

Referring to Fig. 4 a description of the fluid pressure system will be given. A tank 26 is shown as containing a liquid partially filling the tank to the level 27 and having in the upper portion of the tank an elastic fluid which is-admitted through the pipe 28 having therein'the valve 29. The reservoir is designed-to be under constant pressure whereby the liquid therein acts through the pipeon the piston 31 in cylinder 21; Such constant pressure may be maintained by the admission of an elastic fluid through the pipe 28 through the pipe 36, connection and, would ordinarilycomprise a connection to the air pressure line'found in practically all plants. However, the fluid admitted may be steam or any other elastic fluid found convenient. If the valve 29 left open the pressure in the reservoir will at all times remain practically constant. However, if such means is not available at all times the valve 29 may be closed and the fluctuations of the hydraulic fluid through the pipe 30 caused by the reciprocation of the piston 31 may be taken care of by the alternate compression and expansion of the elastic fluid in the upper portion of the reservoir. Means are provided for intermittently admitting hydraulic fluid to the larger cylinder to act against the piston 31. therein in opposition to the pressure constantly maintained on the piston 31. This latter means comprises a sump 32 containing a suitable hydraulic fluid from which fluid is drawn by the pump 33 and forced through the line 34 through the valve 35 and. pipe 36 to "the cylinder 20. Or if the valve occupies a position to the left of that shown the fluid will exhaust from the cylinder 20 back 37, through the groove 38 in the valve and pipe 39 back to the sump 32. 'A relief and by-pass in pro- Vlded for the pump 33 by a pipe 40. The

rate of the flow of the liquid from the pump and thereby the speed of the larger 'p'iston may be regulated and very accurately controlled by means of the valve 41 having an adjustable opening placedat a convenient point in the line 34.

The position of the valve 35'is controlled pby various means comprising a projecting handle 42 extending through, one end of the valve casing and adapted to be grasped manually to move the valve to the right as shown in Fig. 1 against the tension of the spring 43 until the latch 44engages. in the notch 45 on the rod 46 extending from the left end of the valve. The valve is thus held in a position as shown in Fig. 4 until the latch 44 is released by the automatic means now to be described.

Such means comprises a laterally projecting arm 47 rigid with the upper end of the spindle, the outer end of which arm is provided with an eye for receiving the rod 48 which rod is mounted in suitable bearings on the frame and is-adpated to receive a longitudinal movement. The rod 48 is normally maintained in its upper position by means of a spring 49 acting at the lower end thereof. The rod 48 has thereon an adjustable stop 49 adapted to be fastened inany desired position by means of the set screw 50.

The latch 44 is rigidly connected to a rotatable shaft 51 upon which shaft the lever 52 is also rigidly mounted. The spindle 11 in its downward movement causes the arm 48 to engage with the stop 49 which moves the lever 52 and therewith the latch 44 releasing the valve which under the tension of the spring 43 moves to the position shown in Fig. 1 whereby exhaust takes place fromthe cylinder 20 and the pressure in cylinder 21 acting upon the piston 31 causes the piston to move to the left retracting the spindle to its highest position.

In Fig. '5 is shown an arrangement similar to- Fig. 1. In this form, however, the cylinders 20 and 21 have their outer ends closed by cylinder heads 53 and 54 respectively and the pressure fluids are admitted to act on the outer faces of the pistons. In this modification the operation is practically the same with the difference that the power stroke causes the pistons to move to the. left whereas in the form shown in Fig. 1 the application of the fluid to the larger piston causes the pistons to move to the right. Hence in Fig. 5 the rack 24 is mounted underneath the main shaft 14 while in Fig. 1 it is mounted to engage with the opposite-side thereof.

The construction shown in Fig. 1 has advan tages which are one ofthemostimportantfeatures of this invention. In hydraulic transmissions of this type it has been a constant source of'difliculty to prevent leakage around the piston rods; such leakage resulting in in-' convenience and loss of the hydraulic fluid as well as many other annoyances which would accompany the leakage of fluid around a production machine of this type. Since the hydraulic fluid used in transmissions of" this type-often reaches a very high pressure,

such as 1,000 lbs. or even more, it can be The construction shown in Fig. 1 obviates many of these objections. The fluids it may be seen are applied on the opposite sides of the'cylinder' head 23. The fluid acts contantly in the cylinder 21.' Therefore when liquid is admitted into the cylinder 20, since the pressures on the opposite side of the Wall 23 are balanced or nearly so very little leakage, if any, will occur through the packing 33 around the piston rod. Then when .the pressure is relieved from the cylinder if-. any leakage occurs from the cylinder 21' around the piston rod 22 such liquid will pass into the main cylinder and through the pipe 36' into the pump system and be collected therein. Ordinarily the fluid admitted to the larger'cylinder 20 Wouldprobably be of a higher pressure than that'm cylinder 21,

hence any leakage during the power stroke woul'dtend to replenish the supply-of hydraulic fluid in the upper reservoir.

Thus. with the construction shown the packing around the piston rod 22need not be so'strong nor require the attention such as would be the case if the piston rod passed out exteriorly of the cylinder.

;;"The construction of the cylinders shown in Fig. 1 and the means of'assembling is lindrical members having the flanged ends very much simplified and inexpensive to manufacture and. comprises merely two cy- 5 5 and 56 adapted to be bolted together to .57 and 58 to keep form the common cylinder head 23 having the packing 23 therein. The outer ends of the cylinders are provided with cover-plates out dust.

' A brief description of the operation is; as

follows:

Assuming the spindletobe in its upper position with the valve in the position shown in Fig. 1 the-operator grasps the wheel 13' rotating it to. bring the tool into engagement 'with the work. This rotation must take plaice againstthepressure in the cylinder 21 acting-0n the: smaller pistontherein. However, since this piston is relatively small and the fluid acting thereagainst can beof any desired pressure the force required to bring this spindle down needbe only small. The

means shown has the advantage that any time that the'wheel 13 is released the spindle may continue ifhe desires to force the tool on throughits working stroke. However,

will"au tomat ically return to-its' upper position out'of the way of the operator. After the tool has been brought into engagement with the work the operatorthen ordinarilythe operator now throws in the hydraulic feed which is acconiplish edrhy grasping the handle42 and moving the valve to the position shown in Fig. 4. i The spindle the working stroke when the arm 48 engages receives the positive feed until the endof I the-stop 49' tripping the latch mechanism 44 and allowing the Valve toassume the position shown in Fig. 1 whereby the fluid a.

hausts ,from the large cylinder 20 and the pressure acting against the smaller p ston 31 causes the spindle to'move to its uppe'rmost-position.

It may be seen that the arrangement de-.

scribed provides a very efiicient and a novel combination of hydr'aulic-and'manual means for translatingthe drill spindle; The reser-v voir 26. with its fluid connections to, the smaller piston provides "a very flexible and reliable means for automatically returning the spindle to its upper. position but one which can'be easily overcome when'desired' by the application of-manual power to the wheel 13.

The automatic control means comprises but few parts and ls'necessarily accurate and vreliable in its operation. The slide valve" shown prov-ides an exceedingly .de 'endabha valve means for controlling the uid and one which is relatively free froml'aks.

Without further analysis, the foregoing- .will so fully revealthe glst ofthisinvention' thatothers can, by applying current knowl edge, readily ada-ptit for various utilizations "by, retaining one or more of the-features that, from the standpoint of the prior art, fairly constitute essential characteristics of "eitherv the generic or specific aspects of this'invention and, therefor, such adaptations should be, and are intended to be, comprehended within the meaning and range of-equivaleney of the following claims Having thus revealed this invention, I

claim as new and desire to secure the follow- 7 ing combinations and elements, or equivalents thereof, by Letters Patent'of the'United 1. In. amachine tool, a-retatable spindle;

piston'm'eans for translating said"spindle;'

pressure fluid'm'eans connected to act constantly on said piston means to urge it 'in.

' ment of said valve, 'a projection extending from the opposite end of said valve, latch mechanism for enga ing said projection to lock itin the manual y moved position; and means operated'bythes indle for releasing said latch mechanismw ereby the valveis 'moved -to-allow the exhaust of the second fluid pressure means thereby permitting thefirst fluid pressure means to operate said piston means.

'2. F luid' pressure operating means-comprisingfitwo pistons ofdiflerential area; a cylinder for each piston, said cylinders being arranged in tandem; a wall therebetween;a piston rod connecting said pistons extending through said Wall; means for applying a hydraulic fluid under constant pressure to the space between said Wall and the small piston to move said piston in one direction; a system for furnishing hydraulic fluid under pressure; means for alternately admitting fluid therefrom into the space between said wall and the larger piston to move said, pistons in an opposite direction and said last named being alternatively operative to open it to exhaust to said system whereby movement in the first direction is permitted and whereby losses of hydraulic fluid from leakage through said wall are substantially eliminated.

fluid pressure operating means comprising a cylinder; a larger cylinder in tandem therewith; a wall between said cylinders; a piston in each cylinder; a piston rod extending through said wall connecting said pistons; means connected to one of said pistons for taking off power; means for admitting a pressure fluid to act constantly in thespace between said smaller piston and said wall; and means for alternately admitting hydraulic fluid from a pressure system to the space between said larger piston and the walland exhausting said fluid back into said system whereby the pistons are operated in one direction by admission of fluid from said system and in the opposite direction by the first named pressure fluid when said exhaust back into said system is open and fluid leakage through said wall around the piston rod is led to. and retained in the system.

4. Hydraulic operating means for machine tools comprising two pistons of differential area; a cylinder for each piston arranged in tandem, and having a common cylinder,

head; a piston rod connecting saidpistons and extending through said cylinder head; a reservoir for hydraulic fluid; fluid connections therefrom in constant communication 7 with the space between said cylinder head and the pistonofsmaller area; means for placing the reservoir in constant communicat on w1th an elastic fluid under pressure; a closed system for intermittently furnishing hydraulic fluid to the space between said cylinder head and the piston of larger area whereby the pistons are operated in one direction by admission of hydraulic fluid from said system and in the, opposite direction by fluid from saidreservoir when fluid is permitted to exhaust tosaid system and whereby losses from leakage through said wall around, the piston rod are eliminated. p

5. In a machine tool, a rotary spindle; and hydraulic means for translating said spindle comprising two pistons of une ual area, a cylinder for each piston said cylinders being arl'iulged in tandem and having a common cylinder head, a piston rod connecting said pistons and extending through said cylinder head, means operatively connecting one of said pistons to said spindle, a source of hydraulic fluid under pressure in constant communication with the space between said cylinder head and the smaller piston, a closed hydraulic system adapted to alternately admit and exhaust hydraulic fluid from the space between said cylinder head and the larger piston whereby the pistons are caused to move in one direction when hydraulic fluid is admitted from said closed hydraulic system and to move in the opposite direction under pressure of fluid from said constantly communicating source when the exhaust to said closed hydraulic system is open, and whereby losses of hydraulic fluid from leakage around said piston through said wall are eliminated.

6. Fluid pressure operating means comprising a first cylinder and a second cylinder arranged in tandem having a common end wall; pistons in each of said cylinders connected by a piston rod passing through said wall; a first source of fluid pressure in constant communication with the space in said first cylinder between its piston and said wall; a second source of fluid ressure having means for alternately admitting and exhaustdrillingmachine combining a frame; a

drill spindle arranged for vertical translation thereon; power cylinder and piston means horizontally arranged on said frame and operatively connected to said spindle for translating it; means connecting a source of fluid under'pressure to said iston means constantly tending to move said piston means in a direction to retract said spindle; manually operative means to feed said spindle against the force of said fluid pressure means; and means for intermittently admitting a hydraulic fluid to act on said piston means to feed said spindle downward in opposition to said first men- I tioned fluid means, said first mentioned fluid means being operative to retract said spindle and retain it in such retracted position when said hydraulic fluid for feeding is open to exhaust.

8. A machine tool combining .a frame; a spindle mounted for vertical translation thereon; cylinder and differential iston means on said frame arranged with their axis substantially horizontal; connections therefrom to said spindle for translating the latter; fluid pressure; means connected to-a'ct constantly on the piston of smaller area tending to raise saidvspindle; manually openable means forlowering said spindle against the force of saidfluid pressuremeans; and

hydraulic means for electively supplying hydraulic fluid to act on the piston of larger area in a direction to. intermittently feeds-aid spindle against the force of said-fluid pres- 10 'suremeans tending to retract said spindle.

In witness whereof, I have hereunto subscribed my name.

' ADOLPH 1 DE LEEUW. 

